Beams, joists and frames for construction work, for example in aeronautics, civil engineering or architecture, are designed to withstand bending forces acting perpendicularly to the direction of extension of the respective beams. Conventional beams may be implemented as integral parts with flanges at the edges and a web spanning between the flanges.
Such beams used for building of a structural framework, i.e. structural beams, need to be connected at joint locations where beams running at an angle with respect to each other intersect. The intersecting beams need to be kept in alignment with each other, especially at those intersections—therefore, connection techniques have been developed to force-fit or friction-lock the intersecting beams with each other.
For example, if the beams are placed on top of each other with a bottom flange portion of the upper beam lying flat on a top flange portion of the lower beam, congruent holes or cutouts may be provided in the respective flange portions which are brought into alignment in order to attach the bottom flange portion of the upper beam the top flange portion of the lower beam by riveting or bolting. Such a connection requires sufficient edge margins, pitches, material thicknesses and accessibility for riveting tools. Therefore, the connection of the beams is already planned at a design stage in order to provide for the necessary bores. Additional or late modifications after design stage often lead to considerable additional effort in re-planning and are difficult to apply in already manufactured beams.
Other approaches include providing standardized or custom-made interlocking means that have recesses to receive the respective parts of the beams to be interlocked. For example, document U.S. Pat. No. 4,379,651 A discloses a method for rigidly fastening two intersected metal profiles by four L-shaped members enclosing respective side faces of the metal profiles. Document U.S. Pat. No. 729,445 A discloses means for clamping and securing cross metal beams together that include securing clips with edgewise fitting notched partitions for receiving flanges of crossed metal beams.